AC_LIBTOOL_DLOPEN doesn't add -ldl to any LIBS?

[Kevin P. Fleming]

My configure.ac uses AC_LIBTOOL_DLOPEN (among many other macros :-), 
and this works fine. However, this macro does not seem to record its 
results so that the proper dynamic loader library (if one is needed) 
is added to the link commands.

As it stands today, I'm adding the contents of $lt_cv_dlopen_libs to 
LIBS, and that works, but I'm thinking that relying on the value of an 
internal macro variable like that is not the best solution. Any better 
ideas out there?